The present invention relates to the field of electrical connectors, and more specifically relates to a novel type of electrical connector which can be built up from one or several single layered slabs, and which has a novel type of long lasting locking mechanism for locking it to a base portion. Such an electrical connector may be used, for example, for connecting electrical conductors for transmission of electrical signals between a computer and a terminal, or the like.
A conventional type of electrical connector is for example of the type exemplarily shown in perspective view in FIG. 4 of the accompanying drawings; this exemplary connector is a two row type connector. In this drawing, the housing for the connector is designated by the reference numeral 1, and this housing 1 has a mating end 1a on its one side and a terminal fitting end 1b on its other end. The portion of the housing 1 at the connector fitting end 1b is formed as a terminal insertion portion 3 formed with a plurality of sheathed electric wire connection holes 4 opening to the terminal fitting end 1b at fitting openings 6, said terminal insertion portion 3 being open at the top side thereof as seen in the figure, and each of these sheathed electric wire connection holes 4 extends through the housing 1 of the connector to open at its mating end 1a as an insertion hole 5 for a male terminal formed on an external base, not particularly shown. This electrical connector is used, in a manner not particularly shown in the drawings, by fitting a female terminal into each of the plurality of sheathed electric wire connection holes 4, through the fitting openings 6 from the terminal fitting end 1b side of the housing 1, so that the respective ends of said female terminals oppose the respective insertion holes 5. Then the ends of sheathed electrical wires (also not particularly shown) are passed through the fitting openings 1 and are joined to the other ends of said female terminals by crimping or soldering or the like process, and finally a cover (also not shown) is fitted over the open side of the terminal insertion portion 3, so as to securely hold the female terminals in the housing 1. And, in use, the mating end 1a of the connector is approached towards a base (not particularly shown) which has a plurality of male terminals protruding therefrom in an identical configuration to at least some of the insertion holes 5, with the electrical wires connected to the other ends of the female terminals trailing out from the terminal fitting end 1b of the connector, and said male terminals are thus inserted into their said insertion holes 5 so as to mate with the respective female terminals therein and make electrical contact therewith.
Further, as shown in schematic end on view in FIG. 8 of the accompanying drawings, in some cases a locking mechanism for such a connector is conventionally provided, for locking the main body of the connector, designated in this figure by the reference numeral 103, to a base 101 which has such male terminals mounted in it; this structure is of a type disclosed in Japanese Utility Model Laying Open Publication Serial No. 120576, which it is not intended hereby to admit as prior art to the present application except to the extent otherwise required by applicable law, and reference should be made to this publication, should further details be required. The base 101 is typically fixed to a board such as a printed circuit board or soldering or the like, and has a projection 102 on its side, and the main body 103 of the connector has a lock piece 104 integrally formed as projecting from its side, said lock piece 104 being formed with an engaging pawl shape 105 for engaging with the projection 102 of the base 101, and for thus holding the body 103 of the connector squarely against said base 101 with the male terminals (not particularly shown) of said base 101 securely mating with the female terminals (also not shown). In detail, when performing the operation of fitting the body 103 of the connector to the base 101, while said body 103 is being approached towards the base 101, a sloped side 105a of the pawl shape 105 slides against a sloped side 102a of the projection 102, thereby somewhat bending the lock piece 104 against its elasticity and allowing the pawl shape 105 to pass over the projection 102. Thereafter, the inherent elasticity of the lock piece 104 keeps its pawl shape 105 pressed against and engaging with the projection 102, thus holding the body 103 of the connector squarely against the base 101. And, when it is desired to release the body 103 of the connector from the base 101, then typically said body 103 is forcibly pulled away from the base 101, and another sloped side 105b of the pawl shape 105 now slides against another sloped side 102b of the projection 102, thereby again somewhat bending the lock piece 104 against its elasticity and allowing the pawl shape 105 to pass back over the projection 102, to release the body 103 from the base 103. As an alternative, the lock piece may be bent back by hand or by the end of a screw driver or the like, again against its own elasticity.
However, certain problems arise with such conventional structures for an electrical connector, as follows.
First, with reference to the structure of the connector itself as shown in FIG. 4 of the drawings, since the number of sheathed electrical wires to be connected to the terminals of the base board can vary dramatically, depending upon the type of electrical equipment used for each specific application or upon the location in which such equipment is to be fitted, several configurations for the terminals and for the corresponding insertion holes 5 have been adopted. Most typically, they have been arranged either in one row or in two parallel rows as shown in the FIG. 4 example, although configurations employing even more rows have occasionally been utilized. An appropriate one of these configurations is required to be selected for each particular application. Accordingly, although in principle these two types of electrical connector are basically similar, nevertheless the number of component parts that are required to be made in order to fabricate a comprehensive line of connectors incorporating both single row and double row types becomes large, and, since it is required to form the parts for the double row housings and the parts for the single row housings for the two types of connector by different sets of metal dies, accordingly the work and cost of development and tooling are similarly increased. Further, stocking problems and parts management problems are made to be more troublesome. Another problem is that, when the sheathed electrical wires are connected to the female terminals received inside the housing by crimping with a tool as is typical, different crimping tools are required to be utilized for double row housing type connectors and single row housing type connectors, and this is troublesome for the user.
Next, with reference to the locking mechanism for fixing the connector to a base as shown in FIG. 8 of the drawings, the problem with this is that after a long period of service life and many repeated matings and separatings of the connector main body 103 to the base 101, and accompanying bendings to and fro of the lock piece 4, this lock piece 4 may well lose its elasticity due to fatigue, with the result that the locking mechanism may fail in its function. And, because conventionally the lock piece 4 is integrally molded with the main body 3 of the connector, when the lock piece 4 has thus become ineffective for locking, it has heretofore been necessary to change the entire connector in order to remedy this locking problem, which is very troublesome and usually would be neglected by a user, with consequent risk of poor connection problems occurring.